Lightroom CC: Slow performance and scrolling - iMac 2017

Joeri! Bravo!!!!  This work around worked wonders for me on my 5K iMac!! This is fantastic. 

You are very welcome! I'm just so happy I could share this information with everyone here!

Did not work for me. No matter what scale setting I choose it's very slow and sluggish.

Really sorry to hear that, Raphael! I hope you find a different solution!

Is your graphics processor switched on in preferences? Adobe kept switching it off for me when we did screen shares, but I switched it back on prior to doing what Joeri advised and so far its been much better, hope it can get sorted I can totally relate its been so dreadful to work with the software in that condition!

Yes. I tried disabled and re-enabling it. Also reinstalled everything. Still a pain to use. On my Windows PC with a 4K Display Lightroom CC is super fast and super smooth.

only other thing I can think of which I still have as back up plan if this goes wrong again, is connecting another monitor to the iMac so Im not using the iMacs display, not even sure if that would make a difference but worth a try, worse case scenario stick with your PC until an update fixes, saying that Ive had this issue since I got my iMac and every update has failed to fix it 

> Changing color temperature last over 5 sec to take effect

That's not normal, even on a 5K. Is Use Graphics Processor enabled in Preferences > Performance?

I've been using Adobe products since the late 80's, and they've never been responsive to users needs. But they did develop two awesome pieces of software.

Graphics Processor (AMD Radeon R9 M380) was already enabled ...

I have a maxed out iMac 5k 27" retina iMac late 2015 model and LR is terrible on it!! I have tried everything and I mean everything, Did all the common Lr preferences tweaks, reinstalled LR and Mac OS, cleared all catalogues, optimised catalogues, maxed my iMacs ram, had multiple screen shares with apple who says its Adobes issue....had multiple screen shares with adobe that still won't give me answers....every tool I use in LR takes 10-15 seconds to show the adjustment!! I can't even zoom in and out fast....the time it takes to edit my work is costing my business money and I honestly have no idea what else to do...as anyone got any answers yet?? :-(

I actually managed to find the problem. It's LR itself. Lightroom apparently cannot handle the 5k screen well. Change your display to scaled (largest possible) and make sure your thumbnails in LR are quite big. Watch the magic happen. I'm getting a way better performance this way. Good luck!

I've got a very similar spec'ed iMac to yours, and can't see a real difference when following your steps. It still drops frames like crazy. 

Such a shame.. :/ 

Excuse if I sound dumb,  but by change display you mean open the lR app to full display? and increase size of thumbnail you mean lift the view bar at the bottom to highest level to make thumbnails larger? If so.. I tried this and still doesn't work, poor quality...I have got a massive job coming up with thousands of raw images to be edited and I am dreading it! what should take me 2-3 days to edit will be more like 2 weeks :-( really don't know what else to do anymore...buy a new iMac? downgrade? This ongoing issue is costing me time and time costs my business money. :-(

Hey Emma, you're not dumb at all. I spent days figuring it out. And unfortunately it doesn't work for everybody. This is what you do:

Open your preferences/settings (of the mac itself, not LR)
Find "displays"
Look for: resolution. You'll find two options there --> 1 default for display. 2 Scaled.
Set it for scaled --> larger text.
That's what you do on the mac.

In LR: when you're in the grid (hit 'g' on your keyboard) you'll find a slider in the bottom right of the screen to increase or decrease the size of the thumbnails of your pictures. The bigger you make them, the smoother LR runs.

Hope this helps. Will you let me know?

Good luck!

P.S.If you don't see the slider to increase the size of the thumbnails: press 't' on your keyboard. That should make the toolbar appear

I’m sorry but that isn’t a fix or even a workaround. It’s downgrading our computers. I have a 5k Display and i would like to use it when I’m editing photos. Not at 1800p or 4K.

I think that it’s obvious that Lightroom has severe performance problems with the 5k Retina display. Adobe has to optimize Lightroom. And i really hope that the fix comes in the major update after MAX.

Joeri
before you replied, I was playing around last night and I noticed I had got an update for LR,  7.5 so I did that and re opened LR, I opened the app full screen (which I never usually do, haven't a clue why but I never used it full screen) I then made the thumbnails larger and its actually working!!...for now anyway... Im not celebrating to early, but I re- edited a library of raws that last time was a nightmare to edit and everything ran smooth! every tool brush and cropping and zooming in and out. 
So im not going to change the display size as it seems to be working for now.
I pray this is fixed as it will finally mean I can work at the pace I need to! 
I also switched back to "use graphics processor" in settings even though Adobe kept turning it off on my screen shares so Im not sure if that helped too?

I really do hope it was a mixture of the update and the things I have done that as fixed this and it will continue too run the way its supposed to

Thanks Joeri you have been a super star! finally something I have done as made it work!! however if it stops I shall hunt you down haha ;-) 

I have to agree with Nuno I really don't want to downgrade my display when the whole purpose of getting a 5k iMac was to drool over the display whilst editing high MP D850 raw files. 

Shame on adobe for not addressing this LR and 5k iMac issue so many have been having issues with.

I am so happy to hear that it works for you! Happy editing, Emma! :D

@Nuno
I completely 100% agree with you! It is not a fix, merely a coping mechanism. I'm not happy I have to use it, but unfortunately I have no choice. It is either this or just feel irritated by Adobe's stupid program that just happens to be my favourite editing software.

You aren't downgrading your display. It still has the same number of pixels. It just uses them to draw things a bit bigger. If your camera has more than 14MP, you aren't seeing them pixel for pixel on a 5K display anyway. All it does is uses a different algorithm to make the image appear larger, while at the same time reducing the number of calculations required to draw the screen. This workaround works because it reduces the load on the CPU and the GPU. 

In fact, it's an Apple supported solution:

"The Retina display offers scaled resolutions. These allow you to have text and objects appear larger and more visible, or smaller, which provides more space for windows and apps. Your Mac will show either four or five scaled resolution options depending on its model."

https://support.apple.com/en-au/HT202471

No, Ben Fletcher. When I select "Larger text" in display settings, any element on my screen is HUGE. They are so huge that I cannot have two browser windows in split view. Having said that, it definitively feels like I'm downgrading my screen from 27 inch to 19 inch.

You can have two browser windows side by side in full screen, you just need to set the zoom on them too. (The browser will remember your settings next time.) You can change the size of the icons on your desktop (Finder->View->Show View Options)  and you're away. I understand that you *feel* like you are downgrading your machine, however changing a machine's settings to garner optimum performance is all part of the job, really.

To illustrate - The 5K iMac is a *pretty good* (not awesome) machine for editing 4k video, but out of the box it is woeful - almost unusable with any product other than Final Cut Pro. You need to run your OS from an external SSD, set the internal fusion drive as your video cache drive, then host all your 4K footage on a nice quick thunderbolt RAID array to be able to leverage industry standard programs like Davinci Resolve and (to a lesser extent) Premiere Pro and After Effects et al. I have a 2015 iMac set up just as described as above, and I certainly don't feel like I have downgraded it. In fact, it is a video editing weapon.

Same with the one we use for photos - different resolution to leverage Lightroom performance, faster SSD boot drive, files stored on a fast external RAID - the machine hums along and performs it's primary task quickly and quietly. 

Tl:dr Correctly setting up a machine to perform the task that it is required to do is part of owning a machine, not a fault.

P.S. What video card and memory does your machine have? I'm guessing if you hit the apple menu then click "About this Mac" you'll see something like this:
"AMD Radeon R9 M395 2048 MB" Unless you had your machine specifically built to order from Apple, chances are that's your lot. 2GB of graphics memory ain't a lot for a beastly program like Lightroom.

Ben Fletcher, increasing system-widely the size of any visual element *CANNOT* be the solution. It’s a workaround full of compromises, and even then, when the display is set to “Downscale”, Lightroom CC is stuttering and gets stuck while scrolling.

My point is, that Lightroom CC Classic worked perfectly on the same iMac with the same graphics card and the same amount of images.
Even a 5 years old Windows Notebook with an Intel Card handles the new Lightroom CC *EASILY*.

To me it seems that Adobe simply hasn’t Lightroom CC optimized for Mac (yet), which is quite surprising.

Aren’t their main customers Mac users?

Top of the range iMac? You mean an iMac Pro then? Have you tried the solution above? Have you disabled GPU acceleration in the preferences menu? 

Yes, Ben Fletcher, we tried that over and over again.

Heya Ben. Not a pro. Just top of the range iMac. I’ve disabled GPU, enabled GPU. Set huge caches on an external scratch SSD. I’ve upgraded both internal drives to SSDs. Read and write speeds of 1400 and 800 respectively. This machine is fantastically fast with every other application except LightRoom. I have a 4GB GPU and even with a brand new catalogue with say 100 jpgs in it, scrolling is horrendous.

Also. My MacBook Pro (2013) worked perfectly. At full retina resolution and with 2 displays connected.

Paul, have you tried Lightroom CC Classic before? If yes, have you had the same performance issues with that version or did it run smoothly?

Hello! Yup. I run both. Classic is the most problematic.

Hey Paul I stumbled on a post before that had a whole bunch of people with the 2017 machines saying they were having the same problem.... I wonder if that is yet another separate bug... It seems that LR Classic really is getting too big for its boots....

https://feedback.photoshop.com/photoshop_family/topics/lightroom-classic-cc-7-1-so-slow-on-2017-imac

This sounds more like what you are exeriencing? 

Soooo, my situation is not that bad. It's specifically scrolling in the Library Module. That is painfully slow. Even slider adjustments are quick enough. Interface repainting is a little laggy, but above all, Library scrolling is bad.

Ah. Seems that smooth scrolling is literally supported in Windows only. From the Adobe support site: